Increasing subscription revenues will free some of our best national media from dependence on mass audience advertising. But at what cost?

For decades, media critics have lamented American journalism’s over-reliance on advertising and pointed to Europe’s reader-funded press as the better alternative. Less than a decade ago, American newspapers on average depended on advertising for more than 80 percent of their revenues. Since then, many newspapers have moved closer to a 50-50 proposition, and The New York Times . In early December, the Times doubled-down on this approach by .

The upside of the subscription model is that readers are only going to shell out money for something they really want or need. This puts a premium on the highest quality journalism. Indeed, some of the world’s best commercial media are audience rather than advertiser supported. For example, in France, are the sole support for .

The downside is that readers who pay premium prices may also come to equate quality journalism with news that reinforces their deeply held beliefs, creating pressures for a news organization to hew to a consistent political line — likely liberal, .

Another downside is that subscriber-oriented news caters to . As paywalls get firmer, total audiences may decline. It’s quality news, but not for everyone. Given their current funding guidelines, foundations are part of the same problem, not the antidote.

We should not be surprised that the majority of Americans left outside of this supposedly virtuous circle will come to feel even more alienated and distrustful of media that exclude them.

Meanwhile, while liberal media draw their circles ever tighter around themselves, conservatives are fighting to extend their mass reach: Witness Rupert that will challenge those of Facebook and Google, or — still the major news source for most Americans.

What’s missing in the U.S. is what always exists alongside Western Europe’s reader-supported press: — think BBC in England, ARD in Germany, or SVT in Sweden. Large-scale public media ensure that every citizen is exposed to high quality media content, . America’s underfunded and politically pressured PBS and NPR are simply not up to the job.

In short: The only way to avoid the democratic death spiral I’ve described above is to give up the illusion that there is a purely commercial solution to American journalism’s civic crisis.

is professor of media, culture, and communication at New York University.